XMM-Newton observations of PSR B1957+20

Free access article

Issue		A&A Volume 463, Number 2, February IV 2007


Page(s)		L5 - L8
Section		Letters
DOI		http://dx.doi.org/10.1051/0004-6361:20066568

A&A 463, L5-L8 (2007)
DOI: 10.1051/0004-6361:20066568

Letter

XMM-Newton observations of PSR B1957+20

H. H. Huang and W. Becker

Max-Planck-Institut für extraterrestrische Physik, Giessenbachstrasse, 85748 Garching, Germany
e-mail: rhuang@mpe.mpg.de

(Received 13 October 2006 / Accepted 9 January 2007)

Abstract
We report on XMM-Newton observations of the "Black Widow pulsar", PSR B1957+20. The pulsar's X-ray emission is non-thermal and best modeled with a single powerlaw spectrum of photon index 2.03^+0.51_-0.36. No coherent X-ray pulsations at the pulsar's spin-period could be detected, though a strong binary-phase dependence of the X-ray flux is observed for the first time. The data suggest that the majority of the pulsar's X-radiation is emitted from a small part of the binary orbit only. We identified this part as being near to where the radio eclipse takes place. This could mean that the X-rays from PSR B1957+20 are mostly due to intra-shock emission which is strongest when the pulsar wind interacts with the ablated material from the companion star.

Key words: pulsars: individual: PSR B1957+20 -- stars: neutron -- X-rays: stars -- binaries: eclipsing

What is OpenURL?

The OpenURL standard is a protocol for transmission of metadata describing the resource that you wish to access. An OpenURL link contains article metadata and directs it to the OpenURL server of your choice. The OpenURL server can provide access to the resource and also offer complementary services (specific search engine, export of references...). The OpenURL link can be generated by different means.

If your librarian has set up your subscription with an OpenURL resolver, OpenURL links appear automatically on the abstract pages.
You can define your own OpenURL resolver with your EDPS Account. In this case your choice will be given priority over that of your library.
You can use an add-on for your browser (Firefox or I.E.) to display OpenURL links on a page (see http://www.openly.com/openurlref/). You should disable this module if you wish to use the OpenURL server that you or your library have defined.